A change to the Senate healthcare bill proposed by Sens. Ted Cruz, R-Texas, and Mike Lee, R-Utah, hinges on an analysis from the Congressional Budget Office, Republican leaders said Monday.

The results will also determine whether the Republicans support the current Senate healthcare bill, The Hill reported.

"I think it's going to depend entirely — I think a lot of it is going to depend on how CBO evaluates it," Sen. John Thune, R-S.D., said, The Hill reported.

"What does this do to coverage numbers, and how does it affect the overall pool, and how does it affect rates for everybody else that's left in the pool?" Thune also asked.

Under the Cruz-Lee proposal being analyzed by the CBO, insurers would be allowed to offer plans that do not meet Obamacare regulations as long as they also offered a plan that does.

The GOP senators argue it would increase choices for consumers and allow younger and healthier people to buy cheaper plans – but moderates worry only sick people would be left buying Obamacare plans, raising their premiums.

"I do think it's going to be hard to get support," said Senate Finance Committee Chairman Orrin Hatch, R-Utah, The Hill reported.

Sen. John Cornyn, R-Texas, said "a lot of people, including me, support the principle, but we need to know what the [CBO] numbers look like."

Republicans are expected to add $45 billion for opioid abuse treatment to try to win over moderates, who also are looking for Medicaid changes, The Hill reported.